First commit

.gitignore

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+*.wav

README.mkd

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+1. Get an image
+
+![Image of a dog](test.jpg)
+
+2. `$ python spectrogram.py test.jpg` ... `Wrote test.jpg.wav`
+
+3. `$ sox test.jpg.wav -n spectrogram`
+
+![Spectrogram of a dog](spectrogram.png)
+
+Uses [SoX](http://sox.sourceforge.net/sox.html).

run.sh

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+#!/bin/bash
+python spectrogram.py test.jpg
+sox test.jpg.wav -n highpass 200 gain -l -2 spectrogram

spectrogram.py

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+#!/usr/bin/python
+import numpy as np
+import matplotlib.image as mpimg
+import wave
+from array import array
+from progressbar import ProgressBar
+
+def write_column(output_file, pixels, rescale=.1):
+    """ Write a single column of sound """
+    curve = np.fft.ifft(pixels, len(pixels)*2).real
+    curve = np.array((curve-np.average(curve))*rescale, dtype=int)
+    data = array("h", curve).tostring()
+    output_file.writeframes(data)
+
+
+def make_wav(image_filename):
+    """ Make a WAV file having a spectrogram resembling an image """
+    image = mpimg.imread(image_filename)
+    image = np.sum(image, axis = 2).T[:, ::-1]
+    image = image**2
+
+    output_file = wave.open(image_filename+'.wav', 'w')
+    output_file.setparams((1, 2, 44100, 0, 'NONE', 'not compressed'))
+
+    pb = ProgressBar().start()
+    n = float(len(image))
+    for index, column in enumerate(image):
+        write_column(output_file, column)
+        pb.update(index*100/n)
+
+    output_file.close()
+    print "Wrote %s.wav" % image_filename
+
+
+if __name__ == '__main__':
+    import sys
+    make_wav(sys.argv[1])
+